// Copyright (c) Microsoft. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.

/*************************** sha384-512.c ***************************/
/********************* See RFC 4634 for details *********************/
/*
* Description:
*   This file implements the Secure Hash Signature Standard
*   algorithms as defined in the National Institute of Standards
*   and Technology Federal Information Processing Standards
*   Publication (FIPS PUB) 180-1 published on April 17, 1995, 180-2
*   published on August 1, 2002, and the FIPS PUB 180-2 Change
*   Notice published on February 28, 2004.
*
*   A combined document showing all algorithms is available at
*       http://csrc.nist.gov/publications/fips/
*       fips180-2/fips180-2withchangenotice.pdf
*
*   The SHA-384 and SHA-512 algorithms produce 384-bit and 512-bit
*   message digests for a given data stream. It should take about
*   2**n steps to find a message with the same digest as a given
*   message and 2**(n/2) to find any two messages with the same
*   digest, when n is the digest size in bits. Therefore, this
*   algorithm can serve as a means of providing a
*   "fingerprint" for a message.
*
* Portability Issues:
*   SHA-384 and SHA-512 are defined in terms of 64-bit "words",
*   but if USE_32BIT_ONLY is #defined, this code is implemented in
*   terms of 32-bit "words". This code uses <stdint.h> (included
*   via "sha.h") to define the 64, 32 and 8 bit unsigned integer
*   types. If your C compiler does not support 64 bit unsigned
*   integers, and you do not #define USE_32BIT_ONLY, this code is
*   not appropriate.
*
* Caveats:
*   SHA-384 and SHA-512 are designed to work with messages less
*   than 2^128 bits long. This implementation uses
*   SHA384/512Input() to hash the bits that are a multiple of the
*   size of an 8-bit character, and then uses SHA384/256FinalBits()
*   to hash the final few bits of the input.
*
*/

#include <stdlib.h>
#include "azure_c_shared_utility/gballoc.h"

#include "azure_c_shared_utility/sha.h"
#include "azure_c_shared_utility/sha-private.h"

#ifdef USE_32BIT_ONLY
#error IoTHubClient does not support USE_32BIT_ONLY flag
/*
* Define 64-bit arithmetic in terms of 32-bit arithmetic.
* Each 64-bit number is represented in a 2-word array.
* All macros are defined such that the result is the last parameter.
*/

/*
* Define shift, rotate left and rotate right functions
*/
#define SHA512_SHR(bits, word, ret) (                          \
    /* (((uint64_t)((word))) >> (bits)) */                     \
    (ret)[0] = (((bits) < 32) && ((bits) >= 0)) ?              \
      ((word)[0] >> (bits)) : 0,                               \
    (ret)[1] = ((bits) > 32) ? ((word)[0] >> ((bits) - 32)) :  \
      ((bits) == 32) ? (word)[0] :                             \
      ((bits) >= 0) ?                                          \
        (((word)[0] << (32 - (bits))) |                        \
        ((word)[1] >> (bits))) : 0 )

#define SHA512_SHL(bits, word, ret) (                          \
    /* (((uint64_t)(word)) << (bits)) */                       \
    (ret)[0] = ((bits) > 32) ? ((word)[1] << ((bits) - 32)) :  \
         ((bits) == 32) ? (word)[1] :                          \
         ((bits) >= 0) ?                                       \
           (((word)[0] << (bits)) |                            \
           ((word)[1] >> (32 - (bits)))) :                     \
0, \
(ret)[1] = (((bits) < 32) && ((bits) >= 0)) ? \
((word)[1] << (bits)) : 0)

/*
* Define 64-bit OR
*/
#define SHA512_OR(word1, word2, ret) (                         \
    (ret)[0] = (word1)[0] | (word2)[0],                        \
    (ret)[1] = (word1)[1] | (word2)[1] )

/*
* Define 64-bit XOR
*/
#define SHA512_XOR(word1, word2, ret) (                        \
    (ret)[0] = (word1)[0] ^ (word2)[0],                        \
    (ret)[1] = (word1)[1] ^ (word2)[1] )

/*
* Define 64-bit AND
*/
#define SHA512_AND(word1, word2, ret) (                        \
    (ret)[0] = (word1)[0] & (word2)[0],                        \
    (ret)[1] = (word1)[1] & (word2)[1] )

/*
* Define 64-bit TILDA
*/
#define SHA512_TILDA(word, ret)                                \
  ( (ret)[0] = ~(word)[0], (ret)[1] = ~(word)[1] )

/*
* Define 64-bit ADD
*/
#define SHA512_ADD(word1, word2, ret) (                        \
    (ret)[1] = (word1)[1], (ret)[1] += (word2)[1],             \
    (ret)[0] = (word1)[0] + (word2)[0] + ((ret)[1] < (word1)[1]) )

/*
* Add the 4word value in word2 to word1.
*/
static uint32_t ADDTO4_temp, ADDTO4_temp2;
#define SHA512_ADDTO4(word1, word2) (                          \
    ADDTO4_temp = (word1)[3],                                  \
    (word1)[3] += (word2)[3],                                  \
    ADDTO4_temp2 = (word1)[2],                                 \
    (word1)[2] += (word2)[2] + ((word1)[3] < ADDTO4_temp),     \
    ADDTO4_temp = (word1)[1],                                  \
(word1)[1] += (word2)[1] + ((word1)[2] < ADDTO4_temp2), \
(word1)[0] += (word2)[0] + ((word1)[1] < ADDTO4_temp))

/*
* Add the 2word value in word2 to word1.
*/
static uint32_t ADDTO2_temp;
#define SHA512_ADDTO2(word1, word2) (                          \
    ADDTO2_temp = (word1)[1],                                  \
    (word1)[1] += (word2)[1],                                  \
    (word1)[0] += (word2)[0] + ((word1)[1] < ADDTO2_temp) )

/*
* SHA rotate   ((word >> bits) | (word << (64-bits)))
*/
static uint32_t ROTR_temp1[2], ROTR_temp2[2];
#define SHA512_ROTR(bits, word, ret) (                         \
    SHA512_SHR((bits), (word), ROTR_temp1),                    \
    SHA512_SHL(64-(bits), (word), ROTR_temp2),                 \
    SHA512_OR(ROTR_temp1, ROTR_temp2, (ret)) )

/*
* Define the SHA SIGMA and sigma macros
*  SHA512_ROTR(28,word) ^ SHA512_ROTR(34,word) ^ SHA512_ROTR(39,word)
*/
static uint32_t SIGMA0_temp1[2], SIGMA0_temp2[2],
SIGMA0_temp3[2], SIGMA0_temp4[2];
#define SHA512_SIGMA0(word, ret) (                             \
    SHA512_ROTR(28, (word), SIGMA0_temp1),                     \
    SHA512_ROTR(34, (word), SIGMA0_temp2),                     \
    SHA512_ROTR(39, (word), SIGMA0_temp3),                     \
    SHA512_XOR(SIGMA0_temp2, SIGMA0_temp3, SIGMA0_temp4),      \
    SHA512_XOR(SIGMA0_temp1, SIGMA0_temp4, (ret)) )

/*
* SHA512_ROTR(14,word) ^ SHA512_ROTR(18,word) ^ SHA512_ROTR(41,word)
*/
static uint32_t SIGMA1_temp1[2], SIGMA1_temp2[2],
SIGMA1_temp3[2], SIGMA1_temp4[2];
#define SHA512_SIGMA1(word, ret) (                             \
    SHA512_ROTR(14, (word), SIGMA1_temp1),                     \
    SHA512_ROTR(18, (word), SIGMA1_temp2),                     \
    SHA512_ROTR(41, (word), SIGMA1_temp3),                     \
    SHA512_XOR(SIGMA1_temp2, SIGMA1_temp3, SIGMA1_temp4),      \
    SHA512_XOR(SIGMA1_temp1, SIGMA1_temp4, (ret)) )

/*
* (SHA512_ROTR( 1,word) ^ SHA512_ROTR( 8,word) ^ SHA512_SHR( 7,word))
*/
static uint32_t sigma0_temp1[2], sigma0_temp2[2],
sigma0_temp3[2], sigma0_temp4[2];
#define SHA512_sigma0(word, ret) (                             \
    SHA512_ROTR( 1, (word), sigma0_temp1),                     \
    SHA512_ROTR( 8, (word), sigma0_temp2),                     \
    SHA512_SHR( 7, (word), sigma0_temp3),                      \
    SHA512_XOR(sigma0_temp2, sigma0_temp3, sigma0_temp4),      \
    SHA512_XOR(sigma0_temp1, sigma0_temp4, (ret)) )

/*
* (SHA512_ROTR(19,word) ^ SHA512_ROTR(61,word) ^ SHA512_SHR( 6,word))
*/
static uint32_t sigma1_temp1[2], sigma1_temp2[2],
sigma1_temp3[2], sigma1_temp4[2];
#define SHA512_sigma1(word, ret) (                             \
    SHA512_ROTR(19, (word), sigma1_temp1),                     \
    SHA512_ROTR(61, (word), sigma1_temp2),                     \
    SHA512_SHR( 6, (word), sigma1_temp3),                      \
    SHA512_XOR(sigma1_temp2, sigma1_temp3, sigma1_temp4),      \
    SHA512_XOR(sigma1_temp1, sigma1_temp4, (ret)) )

#undef SHA_Ch
#undef SHA_Maj

#ifndef USE_MODIFIED_MACROS
/*
* These definitions are the ones used in FIPS-180-2, section 4.1.3
*  Ch(x,y,z)   ((x & y) ^ (~x & z))
*/
static uint32_t Ch_temp1[2], Ch_temp2[2], Ch_temp3[2];
#define SHA_Ch(x, y, z, ret) (                                 \
    SHA512_AND(x, y, Ch_temp1),                                \
    SHA512_TILDA(x, Ch_temp2),                                 \
    SHA512_AND(Ch_temp2, z, Ch_temp3),                         \
    SHA512_XOR(Ch_temp1, Ch_temp3, (ret)) )
/*
*  Maj(x,y,z)  (((x)&(y)) ^ ((x)&(z)) ^ ((y)&(z)))
*/
static uint32_t Maj_temp1[2], Maj_temp2[2],
Maj_temp3[2], Maj_temp4[2];
#define SHA_Maj(x, y, z, ret) (                                \
    SHA512_AND(x, y, Maj_temp1),                               \
    SHA512_AND(x, z, Maj_temp2),                               \
    SHA512_AND(y, z, Maj_temp3),                               \
    SHA512_XOR(Maj_temp2, Maj_temp3, Maj_temp4),               \
    SHA512_XOR(Maj_temp1, Maj_temp4, (ret)) )

#else /* !USE_32BIT_ONLY */
/*
* These definitions are potentially faster equivalents for the ones
* used in FIPS-180-2, section 4.1.3.
*   ((x & y) ^ (~x & z)) becomes
*   ((x & (y ^ z)) ^ z)
*/
#define SHA_Ch(x, y, z, ret) (                                 \
   (ret)[0] = (((x)[0] & ((y)[0] ^ (z)[0])) ^ (z)[0]),         \
   (ret)[1] = (((x)[1] & ((y)[1] ^ (z)[1])) ^ (z)[1]) )

/*
*   ((x & y) ^ (x & z) ^ (y & z)) becomes
*   ((x & (y | z)) | (y & z))
*/
#define SHA_Maj(x, y, z, ret) (                                 \
   ret[0] = (((x)[0] & ((y)[0] | (z)[0])) | ((y)[0] & (z)[0])), \
   ret[1] = (((x)[1] & ((y)[1] | (z)[1])) | ((y)[1] & (z)[1])) )
#endif /* USE_MODIFIED_MACROS */

/*
* add "length" to the length
*/
static uint32_t addTemp[4] = { 0, 0, 0, 0 };
#define SHA384_512AddLength(context, length) (                        \
    addTemp[3] = (length), SHA512_ADDTO4((context)->Length, addTemp), \
    (context)->Corrupted = (((context)->Length[3] == 0) &&            \
       ((context)->Length[2] == 0) && ((context)->Length[1] == 0) &&  \
       ((context)->Length[0] < 8)) ? 1 : 0 )

/* Local Function Prototypes */
static void SHA384_512Finalize(SHA512Context *context,
    uint8_t Pad_Byte);
static void SHA384_512PadMessage(SHA512Context *context,
    uint8_t Pad_Byte);
static void SHA384_512ProcessMessageBlock(SHA512Context *context);
static int SHA384_512Reset(SHA512Context *context, uint32_t H0[]);
static int SHA384_512ResultN(SHA512Context *context,
    uint8_t Message_Digest[], int HashSize);

/* Initial Hash Values: FIPS-180-2 sections 5.3.3 and 5.3.4 */
static uint32_t SHA384_H0[SHA512HashSize / 4] = {
    0xCBBB9D5D, 0xC1059ED8, 0x629A292A, 0x367CD507, 0x9159015A,
    0x3070DD17, 0x152FECD8, 0xF70E5939, 0x67332667, 0xFFC00B31,
    0x8EB44A87, 0x68581511, 0xDB0C2E0D, 0x64F98FA7, 0x47B5481D,
    0xBEFA4FA4
};

static uint32_t SHA512_H0[SHA512HashSize / 4] = {
    0x6A09E667, 0xF3BCC908, 0xBB67AE85, 0x84CAA73B, 0x3C6EF372,
    0xFE94F82B, 0xA54FF53A, 0x5F1D36F1, 0x510E527F, 0xADE682D1,
    0x9B05688C, 0x2B3E6C1F, 0x1F83D9AB, 0xFB41BD6B, 0x5BE0CD19,
    0x137E2179
};

#else /* !USE_32BIT_ONLY */

/* Define the SHA shift, rotate left and rotate right macro */
#define SHA512_SHR(bits,word)  (((uint64_t)(word)) >> (bits))
#define SHA512_ROTR(bits,word) ((((uint64_t)(word)) >> (bits)) | \
                                (((uint64_t)(word)) << (64-(bits))))

/* Define the SHA SIGMA and sigma macros */
#define SHA512_SIGMA0(word)   \
 (SHA512_ROTR(28,word) ^ SHA512_ROTR(34,word) ^ SHA512_ROTR(39,word))
#define SHA512_SIGMA1(word)   \
 (SHA512_ROTR(14,word) ^ SHA512_ROTR(18,word) ^ SHA512_ROTR(41,word))
#define SHA512_sigma0(word)   \
 (SHA512_ROTR( 1,word) ^ SHA512_ROTR( 8,word) ^ SHA512_SHR( 7,word))
#define SHA512_sigma1(word)   \
 (SHA512_ROTR(19,word) ^ SHA512_ROTR(61,word) ^ SHA512_SHR( 6,word))

/*
* add "length" to the length
*/
#define SHA384_512AddLength(context, length)                   \
   (addTemp = context->Length_Low, context->Corrupted =        \
    ((context->Length_Low += length) < addTemp) &&             \
    (++context->Length_High == 0) ? 1 : 0)

/* Local Function Prototypes */
static void SHA384_512Finalize(SHA512Context *context,
    uint8_t Pad_Byte);
static void SHA384_512PadMessage(SHA512Context *context,
    uint8_t Pad_Byte);
static void SHA384_512ProcessMessageBlock(SHA512Context *context);
static int SHA384_512Reset(SHA512Context *context, uint64_t H0[]);
static int SHA384_512ResultN(SHA512Context *context,
    uint8_t Message_Digest[], int HashSize);

/* Initial Hash Values: FIPS-180-2 sections 5.3.3 and 5.3.4 */
static uint64_t SHA384_H0[] = {
    0xCBBB9D5DC1059ED8ull, 0x629A292A367CD507ull, 0x9159015A3070DD17ull,
    0x152FECD8F70E5939ull, 0x67332667FFC00B31ull, 0x8EB44A8768581511ull,
    0xDB0C2E0D64F98FA7ull, 0x47B5481DBEFA4FA4ull
};
static uint64_t SHA512_H0[] = {
    0x6A09E667F3BCC908ull, 0xBB67AE8584CAA73Bull, 0x3C6EF372FE94F82Bull,
    0xA54FF53A5F1D36F1ull, 0x510E527FADE682D1ull, 0x9B05688C2B3E6C1Full,
    0x1F83D9ABFB41BD6Bull, 0x5BE0CD19137E2179ull
};

#endif /* USE_32BIT_ONLY */

/*
* SHA384Reset
*
* Description:
*   This function will initialize the SHA384Context in preparation
*   for computing a new SHA384 message digest.
*
* Parameters:
*   context: [in/out]
*     The context to reset.
*
* Returns:
*   sha Error Code.
*
*/
int SHA384Reset(SHA384Context *context)
{
    return SHA384_512Reset(context, SHA384_H0);
}

/*
* SHA384Input
*
* Description:
*   This function accepts an array of octets as the next portion
*   of the message.
*
* Parameters:
*   context: [in/out]
*     The SHA context to update
*   message_array: [in]
*     An array of characters representing the next portion of
*     the message.
*   length: [in]
*     The length of the message in message_array
*
* Returns:
*   sha Error Code.
*
*/
int SHA384Input(SHA384Context *context,
    const uint8_t *message_array, unsigned int length)
{
    return SHA512Input(context, message_array, length);
}

/*
* SHA384FinalBits
*
* Description:
*   This function will add in any final bits of the message.
*
* Parameters:
*   context: [in/out]
*     The SHA context to update
*   message_bits: [in]
*     The final bits of the message, in the upper portion of the
*     byte. (Use 0b###00000 instead of 0b00000### to input the
*     three bits ###.)
*   length: [in]
*     The number of bits in message_bits, between 1 and 7.
*
* Returns:
*   sha Error Code.
*
*/
int SHA384FinalBits(SHA384Context *context,
    const uint8_t message_bits, unsigned int length)
{
    return SHA512FinalBits(context, message_bits, length);
}

/*
* SHA384Result
*
* Description:
*   This function will return the 384-bit message
*   digest into the Message_Digest array provided by the caller.
*   NOTE: The first octet of hash is stored in the 0th element,
*      the last octet of hash in the 48th element.
*
* Parameters:
*   context: [in/out]
*     The context to use to calculate the SHA hash.
*   Message_Digest: [out]
*     Where the digest is returned.
*
* Returns:
*   sha Error Code.
*
*/
int SHA384Result(SHA384Context *context,
    uint8_t Message_Digest[SHA384HashSize])
{
    return SHA384_512ResultN(context, Message_Digest, SHA384HashSize);
}

/*
* SHA512Reset
*
* Description:
*   This function will initialize the SHA512Context in preparation
*   for computing a new SHA512 message digest.
*
* Parameters:
*   context: [in/out]
*     The context to reset.
*
* Returns:
*   sha Error Code.
*
*/
int SHA512Reset(SHA512Context *context)
{
    return SHA384_512Reset(context, SHA512_H0);
}

/*
* SHA512Input
*
* Description:
*   This function accepts an array of octets as the next portion
*   of the message.
*
* Parameters:
*   context: [in/out]
*     The SHA context to update
*   message_array: [in]
*     An array of characters representing the next portion of
*     the message.
*   length: [in]
*     The length of the message in message_array
*
* Returns:
*   sha Error Code.
*
*/
int SHA512Input(SHA512Context *context,
    const uint8_t *message_array,
    unsigned int length)
{
    uint64_t addTemp;
    if (!length)
        return shaSuccess;
    
    if (length > (sizeof(context->Message_Block) / sizeof(context->Message_Block[0])))
        return shaBadParam;

    if (!context || !message_array)
        return shaNull;

    if (context->Computed) {
        context->Corrupted = shaStateError;
        return shaStateError;
    }

    if (context->Corrupted)
        return context->Corrupted;

    while (length-- && !context->Corrupted) {
        if (context->Message_Block_Index < SHA512_Message_Block_Size)
        {
            context->Message_Block[context->Message_Block_Index++] =
                (*message_array & 0xFF);

            if (!SHA384_512AddLength(context, 8) &&
                (context->Message_Block_Index == SHA512_Message_Block_Size))
                SHA384_512ProcessMessageBlock(context);

            message_array++;
        }
        else
        {
            context->Corrupted = shaBadParam;
        }
    }

    return context->Corrupted;
}

/*
* SHA512FinalBits
*
* Description:
*   This function will add in any final bits of the message.
*
* Parameters:
*   context: [in/out]
*     The SHA context to update
*   message_bits: [in]
*     The final bits of the message, in the upper portion of the
*     byte. (Use 0b###00000 instead of 0b00000### to input the
*     three bits ###.)
*   length: [in]
*     The number of bits in message_bits, between 1 and 7.
*
* Returns:
*   sha Error Code.
*
*/
int SHA512FinalBits(SHA512Context *context,
    const uint8_t message_bits, unsigned int length)
{
    uint64_t addTemp;
    uint8_t masks[8] = {
        /* 0 0b00000000 */ 0x00, /* 1 0b10000000 */ 0x80,
        /* 2 0b11000000 */ 0xC0, /* 3 0b11100000 */ 0xE0,
        /* 4 0b11110000 */ 0xF0, /* 5 0b11111000 */ 0xF8,
        /* 6 0b11111100 */ 0xFC, /* 7 0b11111110 */ 0xFE
    };
    uint8_t markbit[8] = {
        /* 0 0b10000000 */ 0x80, /* 1 0b01000000 */ 0x40,
        /* 2 0b00100000 */ 0x20, /* 3 0b00010000 */ 0x10,
        /* 4 0b00001000 */ 0x08, /* 5 0b00000100 */ 0x04,
        /* 6 0b00000010 */ 0x02, /* 7 0b00000001 */ 0x01
    };

    if (!length)
        return shaSuccess;

    if (!context)
        return shaNull;

    if ((context->Computed) || (length >= 8) || (length == 0)) {
        context->Corrupted = shaStateError;
        return shaStateError;
    }

    if (context->Corrupted)
        return context->Corrupted;

    SHA384_512AddLength(context, length);
    SHA384_512Finalize(context, (uint8_t)
        ((message_bits & masks[length]) | markbit[length]));

    return shaSuccess;
}

/*
* SHA384_512Finalize
*
* Description:
*   This helper function finishes off the digest calculations.
*
* Parameters:
*   context: [in/out]
*     The SHA context to update
*   Pad_Byte: [in]
*     The last byte to add to the digest before the 0-padding
*     and length. This will contain the last bits of the message
*     followed by another single bit. If the message was an
*     exact multiple of 8-bits long, Pad_Byte will be 0x80.
*
* Returns:
*   sha Error Code.
*
*/
static void SHA384_512Finalize(SHA512Context *context,
    uint8_t Pad_Byte)
{
    int_least16_t i;
    SHA384_512PadMessage(context, Pad_Byte);
    /* message may be sensitive, clear it out */
    for (i = 0; i < SHA512_Message_Block_Size; ++i)
        context->Message_Block[i] = 0;
#ifdef USE_32BIT_ONLY    /* and clear length */
    context->Length[0] = context->Length[1] = 0;
    context->Length[2] = context->Length[3] = 0;
#else /* !USE_32BIT_ONLY */
    context->Length_Low = 0;
    context->Length_High = 0;
#endif /* USE_32BIT_ONLY */
    context->Computed = 1;
}

/*
* SHA512Result
*
* Description:
*   This function will return the 512-bit message
*   digest into the Message_Digest array provided by the caller.
*   NOTE: The first octet of hash is stored in the 0th element,
*      the last octet of hash in the 64th element.
*
* Parameters:
*   context: [in/out]
*     The context to use to calculate the SHA hash.
*   Message_Digest: [out]
*     Where the digest is returned.
*
* Returns:
*   sha Error Code.
*
*/
int SHA512Result(SHA512Context *context,
    uint8_t Message_Digest[SHA512HashSize])
{
    return SHA384_512ResultN(context, Message_Digest, SHA512HashSize);
}

/*
* SHA384_512PadMessage
*
* Description:
*   According to the standard, the message must be padded to an
*   even 1024 bits. The first padding bit must be a '1'. The
*   last 128 bits represent the length of the original message.
*   All bits in between should be 0. This helper function will
*   pad the message according to those rules by filling the
*   Message_Block array accordingly. When it returns, it can be
*   assumed that the message digest has been computed.
*
* Parameters:
*   context: [in/out]
*     The context to pad
*   Pad_Byte: [in]
*     The last byte to add to the digest before the 0-padding
*     and length. This will contain the last bits of the message
*     followed by another single bit. If the message was an
*     exact multiple of 8-bits long, Pad_Byte will be 0x80.
*
* Returns:
*   Nothing.
*
*/
static void SHA384_512PadMessage(SHA512Context *context,
    uint8_t Pad_Byte)
{
    /*
    * Check to see if the current message block is too small to hold
    * the initial padding bits and length. If so, we will pad the
    * block, process it, and then continue padding into a second
    * block.
    */
    if (context->Message_Block_Index >= (SHA512_Message_Block_Size - 16)) {
        context->Message_Block[context->Message_Block_Index++] = Pad_Byte;
        while (context->Message_Block_Index < SHA512_Message_Block_Size)
            context->Message_Block[context->Message_Block_Index++] = 0;

        SHA384_512ProcessMessageBlock(context);
    }
    else
        context->Message_Block[context->Message_Block_Index++] = Pad_Byte;

    while (context->Message_Block_Index < (SHA512_Message_Block_Size - 16))
        context->Message_Block[context->Message_Block_Index++] = 0;

    /*
    * Store the message length as the last 16 octets
    */
#ifdef USE_32BIT_ONLY
    context->Message_Block[112] = (uint8_t)(context->Length[0] >> 24);
    context->Message_Block[113] = (uint8_t)(context->Length[0] >> 16);
    context->Message_Block[114] = (uint8_t)(context->Length[0] >> 8);
    context->Message_Block[115] = (uint8_t)(context->Length[0]);
    context->Message_Block[116] = (uint8_t)(context->Length[1] >> 24);
    context->Message_Block[117] = (uint8_t)(context->Length[1] >> 16);
    context->Message_Block[118] = (uint8_t)(context->Length[1] >> 8);
    context->Message_Block[119] = (uint8_t)(context->Length[1]);

    context->Message_Block[120] = (uint8_t)(context->Length[2] >> 24);
    context->Message_Block[121] = (uint8_t)(context->Length[2] >> 16);
    context->Message_Block[122] = (uint8_t)(context->Length[2] >> 8);
    context->Message_Block[123] = (uint8_t)(context->Length[2]);
    context->Message_Block[124] = (uint8_t)(context->Length[3] >> 24);
    context->Message_Block[125] = (uint8_t)(context->Length[3] >> 16);
    context->Message_Block[126] = (uint8_t)(context->Length[3] >> 8);
    context->Message_Block[127] = (uint8_t)(context->Length[3]);
#else /* !USE_32BIT_ONLY */
    context->Message_Block[112] = (uint8_t)(context->Length_High >> 56);
    context->Message_Block[113] = (uint8_t)(context->Length_High >> 48);
    context->Message_Block[114] = (uint8_t)(context->Length_High >> 40);
    context->Message_Block[115] = (uint8_t)(context->Length_High >> 32);
    context->Message_Block[116] = (uint8_t)(context->Length_High >> 24);
    context->Message_Block[117] = (uint8_t)(context->Length_High >> 16);
    context->Message_Block[118] = (uint8_t)(context->Length_High >> 8);
    context->Message_Block[119] = (uint8_t)(context->Length_High);

    context->Message_Block[120] = (uint8_t)(context->Length_Low >> 56);
    context->Message_Block[121] = (uint8_t)(context->Length_Low >> 48);
    context->Message_Block[122] = (uint8_t)(context->Length_Low >> 40);
    context->Message_Block[123] = (uint8_t)(context->Length_Low >> 32);
    context->Message_Block[124] = (uint8_t)(context->Length_Low >> 24);
    context->Message_Block[125] = (uint8_t)(context->Length_Low >> 16);
    context->Message_Block[126] = (uint8_t)(context->Length_Low >> 8);
    context->Message_Block[127] = (uint8_t)(context->Length_Low);
#endif /* USE_32BIT_ONLY */

    SHA384_512ProcessMessageBlock(context);
}

/*
* SHA384_512ProcessMessageBlock
*
* Description:
*   This helper function will process the next 1024 bits of the
*   message stored in the Message_Block array.
*
* Parameters:
*   context: [in/out]
*     The SHA context to update
*
* Returns:
*   Nothing.
*
* Comments:
*   Many of the variable names in this code, especially the
*   single character names, were used because those were the
*   names used in the publication.
*
*
*/
static void SHA384_512ProcessMessageBlock(SHA512Context *context)
{
    /* Constants defined in FIPS-180-2, section 4.2.3 */
#ifdef USE_32BIT_ONLY
    static const uint32_t K[80 * 2] = {
        0x428A2F98, 0xD728AE22, 0x71374491, 0x23EF65CD, 0xB5C0FBCF,
        0xEC4D3B2F, 0xE9B5DBA5, 0x8189DBBC, 0x3956C25B, 0xF348B538,
        0x59F111F1, 0xB605D019, 0x923F82A4, 0xAF194F9B, 0xAB1C5ED5,
        0xDA6D8118, 0xD807AA98, 0xA3030242, 0x12835B01, 0x45706FBE,
        0x243185BE, 0x4EE4B28C, 0x550C7DC3, 0xD5FFB4E2, 0x72BE5D74,
        0xF27B896F, 0x80DEB1FE, 0x3B1696B1, 0x9BDC06A7, 0x25C71235,
        0xC19BF174, 0xCF692694, 0xE49B69C1, 0x9EF14AD2, 0xEFBE4786,
        0x384F25E3, 0x0FC19DC6, 0x8B8CD5B5, 0x240CA1CC, 0x77AC9C65,
        0x2DE92C6F, 0x592B0275, 0x4A7484AA, 0x6EA6E483, 0x5CB0A9DC,
        0xBD41FBD4, 0x76F988DA, 0x831153B5, 0x983E5152, 0xEE66DFAB,
        0xA831C66D, 0x2DB43210, 0xB00327C8, 0x98FB213F, 0xBF597FC7,
        0xBEEF0EE4, 0xC6E00BF3, 0x3DA88FC2, 0xD5A79147, 0x930AA725,
        0x06CA6351, 0xE003826F, 0x14292967, 0x0A0E6E70, 0x27B70A85,
        0x46D22FFC, 0x2E1B2138, 0x5C26C926, 0x4D2C6DFC, 0x5AC42AED,
        0x53380D13, 0x9D95B3DF, 0x650A7354, 0x8BAF63DE, 0x766A0ABB,
        0x3C77B2A8, 0x81C2C92E, 0x47EDAEE6, 0x92722C85, 0x1482353B,
        0xA2BFE8A1, 0x4CF10364, 0xA81A664B, 0xBC423001, 0xC24B8B70,
        0xD0F89791, 0xC76C51A3, 0x0654BE30, 0xD192E819, 0xD6EF5218,
        0xD6990624, 0x5565A910, 0xF40E3585, 0x5771202A, 0x106AA070,
        0x32BBD1B8, 0x19A4C116, 0xB8D2D0C8, 0x1E376C08, 0x5141AB53,
        0x2748774C, 0xDF8EEB99, 0x34B0BCB5, 0xE19B48A8, 0x391C0CB3,
        0xC5C95A63, 0x4ED8AA4A, 0xE3418ACB, 0x5B9CCA4F, 0x7763E373,
        0x682E6FF3, 0xD6B2B8A3, 0x748F82EE, 0x5DEFB2FC, 0x78A5636F,
        0x43172F60, 0x84C87814, 0xA1F0AB72, 0x8CC70208, 0x1A6439EC,
        0x90BEFFFA, 0x23631E28, 0xA4506CEB, 0xDE82BDE9, 0xBEF9A3F7,
        0xB2C67915, 0xC67178F2, 0xE372532B, 0xCA273ECE, 0xEA26619C,
        0xD186B8C7, 0x21C0C207, 0xEADA7DD6, 0xCDE0EB1E, 0xF57D4F7F,
        0xEE6ED178, 0x06F067AA, 0x72176FBA, 0x0A637DC5, 0xA2C898A6,
        0x113F9804, 0xBEF90DAE, 0x1B710B35, 0x131C471B, 0x28DB77F5,
        0x23047D84, 0x32CAAB7B, 0x40C72493, 0x3C9EBE0A, 0x15C9BEBC,
        0x431D67C4, 0x9C100D4C, 0x4CC5D4BE, 0xCB3E42B6, 0x597F299C,
        0xFC657E2A, 0x5FCB6FAB, 0x3AD6FAEC, 0x6C44198C, 0x4A475817
    };
    int     t, t2, t8;                  /* Loop counter */
    uint32_t  temp1[2], temp2[2],       /* Temporary word values */
        temp3[2], temp4[2], temp5[2];
    uint32_t  W[2 * 80];                  /* Word sequence */
    uint32_t  A[2], B[2], C[2], D[2],   /* Word buffers */
        E[2], F[2], G[2], H[2];

    /* Initialize the first 16 words in the array W */
    for (t = t2 = t8 = 0; t < 16; t++, t8 += 8) {
        W[t2++] = ((((uint32_t)context->Message_Block[t8])) << 24) |
            ((((uint32_t)context->Message_Block[t8 + 1])) << 16) |
            ((((uint32_t)context->Message_Block[t8 + 2])) << 8) |
            ((((uint32_t)context->Message_Block[t8 + 3])));
        W[t2++] = ((((uint32_t)context->Message_Block[t8 + 4])) << 24) |
            ((((uint32_t)context->Message_Block[t8 + 5])) << 16) |
            ((((uint32_t)context->Message_Block[t8 + 6])) << 8) |
            ((((uint32_t)context->Message_Block[t8 + 7])));
    }

    for (t = 16; t < 80; t++, t2 += 2) {
        /* W[t] = SHA512_sigma1(W[t-2]) + W[t-7] +
        SHA512_sigma0(W[t-15]) + W[t-16]; */
        uint32_t *Wt2 = &W[t2 - 2 * 2];
        uint32_t *Wt7 = &W[t2 - 7 * 2];
        uint32_t *Wt15 = &W[t2 - 15 * 2];
        uint32_t *Wt16 = &W[t2 - 16 * 2];
        SHA512_sigma1(Wt2, temp1);
        SHA512_ADD(temp1, Wt7, temp2);
        SHA512_sigma0(Wt15, temp1);
        SHA512_ADD(temp1, Wt16, temp3);
        SHA512_ADD(temp2, temp3, &W[t2]);
    }

    A[0] = context->Intermediate_Hash[0];
    A[1] = context->Intermediate_Hash[1];
    B[0] = context->Intermediate_Hash[2];
    B[1] = context->Intermediate_Hash[3];
    C[0] = context->Intermediate_Hash[4];
    C[1] = context->Intermediate_Hash[5];
    D[0] = context->Intermediate_Hash[6];
    D[1] = context->Intermediate_Hash[7];
    E[0] = context->Intermediate_Hash[8];
    E[1] = context->Intermediate_Hash[9];
    F[0] = context->Intermediate_Hash[10];
    F[1] = context->Intermediate_Hash[11];
    G[0] = context->Intermediate_Hash[12];
    G[1] = context->Intermediate_Hash[13];
    H[0] = context->Intermediate_Hash[14];
    H[1] = context->Intermediate_Hash[15];

    for (t = t2 = 0; t < 80; t++, t2 += 2) {
        /*
        * temp1 = H + SHA512_SIGMA1(E) + SHA_Ch(E,F,G) + K[t] + W[t];
        */
        SHA512_SIGMA1(E, temp1);
        SHA512_ADD(H, temp1, temp2);
        SHA_Ch(E, F, G, temp3);
        SHA512_ADD(temp2, temp3, temp4);
        SHA512_ADD(&K[t2], &W[t2], temp5);
        SHA512_ADD(temp4, temp5, temp1);
        /*
        * temp2 = SHA512_SIGMA0(A) + SHA_Maj(A,B,C);
        */
        SHA512_SIGMA0(A, temp3);
        SHA_Maj(A, B, C, temp4);
        SHA512_ADD(temp3, temp4, temp2);
        H[0] = G[0]; H[1] = G[1];
        G[0] = F[0]; G[1] = F[1];
        F[0] = E[0]; F[1] = E[1];
        SHA512_ADD(D, temp1, E);
        D[0] = C[0]; D[1] = C[1];
        C[0] = B[0]; C[1] = B[1];
        B[0] = A[0]; B[1] = A[1];
        SHA512_ADD(temp1, temp2, A);
    }

    SHA512_ADDTO2(&context->Intermediate_Hash[0], A);
    SHA512_ADDTO2(&context->Intermediate_Hash[2], B);
    SHA512_ADDTO2(&context->Intermediate_Hash[4], C);
    SHA512_ADDTO2(&context->Intermediate_Hash[6], D);
    SHA512_ADDTO2(&context->Intermediate_Hash[8], E);
    SHA512_ADDTO2(&context->Intermediate_Hash[10], F);
    SHA512_ADDTO2(&context->Intermediate_Hash[12], G);
    SHA512_ADDTO2(&context->Intermediate_Hash[14], H);

#else /* !USE_32BIT_ONLY */
    static const uint64_t K[80] = {
        0x428A2F98D728AE22ull, 0x7137449123EF65CDull, 0xB5C0FBCFEC4D3B2Full,
        0xE9B5DBA58189DBBCull, 0x3956C25BF348B538ull, 0x59F111F1B605D019ull,
        0x923F82A4AF194F9Bull, 0xAB1C5ED5DA6D8118ull, 0xD807AA98A3030242ull,
        0x12835B0145706FBEull, 0x243185BE4EE4B28Cull, 0x550C7DC3D5FFB4E2ull,
        0x72BE5D74F27B896Full, 0x80DEB1FE3B1696B1ull, 0x9BDC06A725C71235ull,
        0xC19BF174CF692694ull, 0xE49B69C19EF14AD2ull, 0xEFBE4786384F25E3ull,
        0x0FC19DC68B8CD5B5ull, 0x240CA1CC77AC9C65ull, 0x2DE92C6F592B0275ull,
        0x4A7484AA6EA6E483ull, 0x5CB0A9DCBD41FBD4ull, 0x76F988DA831153B5ull,
        0x983E5152EE66DFABull, 0xA831C66D2DB43210ull, 0xB00327C898FB213Full,
        0xBF597FC7BEEF0EE4ull, 0xC6E00BF33DA88FC2ull, 0xD5A79147930AA725ull,
        0x06CA6351E003826Full, 0x142929670A0E6E70ull, 0x27B70A8546D22FFCull,
        0x2E1B21385C26C926ull, 0x4D2C6DFC5AC42AEDull, 0x53380D139D95B3DFull,
        0x650A73548BAF63DEull, 0x766A0ABB3C77B2A8ull, 0x81C2C92E47EDAEE6ull,
        0x92722C851482353Bull, 0xA2BFE8A14CF10364ull, 0xA81A664BBC423001ull,
        0xC24B8B70D0F89791ull, 0xC76C51A30654BE30ull, 0xD192E819D6EF5218ull,
        0xD69906245565A910ull, 0xF40E35855771202Aull, 0x106AA07032BBD1B8ull,
        0x19A4C116B8D2D0C8ull, 0x1E376C085141AB53ull, 0x2748774CDF8EEB99ull,
        0x34B0BCB5E19B48A8ull, 0x391C0CB3C5C95A63ull, 0x4ED8AA4AE3418ACBull,
        0x5B9CCA4F7763E373ull, 0x682E6FF3D6B2B8A3ull, 0x748F82EE5DEFB2FCull,
        0x78A5636F43172F60ull, 0x84C87814A1F0AB72ull, 0x8CC702081A6439ECull,
        0x90BEFFFA23631E28ull, 0xA4506CEBDE82BDE9ull, 0xBEF9A3F7B2C67915ull,
        0xC67178F2E372532Bull, 0xCA273ECEEA26619Cull, 0xD186B8C721C0C207ull,
        0xEADA7DD6CDE0EB1Eull, 0xF57D4F7FEE6ED178ull, 0x06F067AA72176FBAull,
        0x0A637DC5A2C898A6ull, 0x113F9804BEF90DAEull, 0x1B710B35131C471Bull,
        0x28DB77F523047D84ull, 0x32CAAB7B40C72493ull, 0x3C9EBE0A15C9BEBCull,
        0x431D67C49C100D4Cull, 0x4CC5D4BECB3E42B6ull, 0x597F299CFC657E2Aull,
        0x5FCB6FAB3AD6FAECull, 0x6C44198C4A475817ull
    };
    int        t, t8;                   /* Loop counter */
    uint64_t   temp1, temp2;            /* Temporary word value */
    uint64_t   W[80];                   /* Word sequence */
    uint64_t   A, B, C, D, E, F, G, H;  /* Word buffers */

    /*
    * Initialize the first 16 words in the array W
    */
    for (t = t8 = 0; t < 16; t++, t8 += 8)
        W[t] = ((uint64_t)(context->Message_Block[t8]) << 56) |
        ((uint64_t)(context->Message_Block[t8 + 1]) << 48) |
        ((uint64_t)(context->Message_Block[t8 + 2]) << 40) |
        ((uint64_t)(context->Message_Block[t8 + 3]) << 32) |
        ((uint64_t)(context->Message_Block[t8 + 4]) << 24) |
        ((uint64_t)(context->Message_Block[t8 + 5]) << 16) |
        ((uint64_t)(context->Message_Block[t8 + 6]) << 8) |
        ((uint64_t)(context->Message_Block[t8 + 7]));

    for (t = 16; t < 80; t++)
        W[t] = SHA512_sigma1(W[t - 2]) + W[t - 7] +
        SHA512_sigma0(W[t - 15]) + W[t - 16];

    A = context->Intermediate_Hash[0];
    B = context->Intermediate_Hash[1];
    C = context->Intermediate_Hash[2];
    D = context->Intermediate_Hash[3];
    E = context->Intermediate_Hash[4];
    F = context->Intermediate_Hash[5];
    G = context->Intermediate_Hash[6];
    H = context->Intermediate_Hash[7];

    for (t = 0; t < 80; t++) {
        temp1 = H + SHA512_SIGMA1(E) + SHA_Ch(E, F, G) + K[t] + W[t];
        temp2 = SHA512_SIGMA0(A) + SHA_Maj(A, B, C);
        H = G;
        G = F;
        F = E;
        E = D + temp1;
        D = C;
        C = B;
        B = A;
        A = temp1 + temp2;
    }

    context->Intermediate_Hash[0] += A;
    context->Intermediate_Hash[1] += B;
    context->Intermediate_Hash[2] += C;
    context->Intermediate_Hash[3] += D;
    context->Intermediate_Hash[4] += E;
    context->Intermediate_Hash[5] += F;
    context->Intermediate_Hash[6] += G;
    context->Intermediate_Hash[7] += H;
#endif /* USE_32BIT_ONLY */

    context->Message_Block_Index = 0;
}

/*
* SHA384_512Reset
*
* Description:
*   This helper function will initialize the SHA512Context in
*   preparation for computing a new SHA384 or SHA512 message
*   digest.
*
* Parameters:
*   context: [in/out]
*     The context to reset.
*   H0
*     The initial hash value to use.
*
* Returns:
*   sha Error Code.
*
*/
#ifdef USE_32BIT_ONLY
static int SHA384_512Reset(SHA512Context *context, uint32_t H0[])
#else /* !USE_32BIT_ONLY */
static int SHA384_512Reset(SHA512Context *context, uint64_t H0[])
#endif /* USE_32BIT_ONLY */
{
    int i;
    if (!context)
        return shaNull;

    context->Message_Block_Index = 0;

#ifdef USE_32BIT_ONLY
    context->Length[0] = context->Length[1] = 0;
    context->Length[2] = context->Length[3] = 0;

    for (i = 0; i < SHA512HashSize / 4; i++)
        context->Intermediate_Hash[i] = H0[i];
#else /* !USE_32BIT_ONLY */
    context->Length_High = context->Length_Low = 0;

    for (i = 0; i < SHA512HashSize / 8; i++)
        context->Intermediate_Hash[i] = H0[i];
#endif /* USE_32BIT_ONLY */

    context->Computed = 0;
    context->Corrupted = 0;

    return shaSuccess;
}

/*
* SHA384_512ResultN
*
* Description:
*   This helper function will return the 384-bit or 512-bit message
*   digest into the Message_Digest array provided by the caller.
*   NOTE: The first octet of hash is stored in the 0th element,
*      the last octet of hash in the 48th/64th element.
*
* Parameters:
*   context: [in/out]
*     The context to use to calculate the SHA hash.
*   Message_Digest: [out]
*     Where the digest is returned.
*   HashSize: [in]
*     The size of the hash, either 48 or 64.
*
* Returns:
*   sha Error Code.
*
*/
static int SHA384_512ResultN(SHA512Context *context,
    uint8_t Message_Digest[], int HashSize)
{
    int i;

#ifdef USE_32BIT_ONLY
    int i2;
#endif /* USE_32BIT_ONLY */

    if (!context || !Message_Digest)
        return shaNull;

    if (context->Corrupted)
        return context->Corrupted;

    if (!context->Computed)
        SHA384_512Finalize(context, 0x80);

#ifdef USE_32BIT_ONLY
    for (i = i2 = 0; i < HashSize;) {
        Message_Digest[i++] = (uint8_t)(context->Intermediate_Hash[i2] >> 24);
        Message_Digest[i++] = (uint8_t)(context->Intermediate_Hash[i2] >> 16);
        Message_Digest[i++] = (uint8_t)(context->Intermediate_Hash[i2] >> 8);
        Message_Digest[i++] = (uint8_t)(context->Intermediate_Hash[i2++]);
        Message_Digest[i++] = (uint8_t)(context->Intermediate_Hash[i2] >> 24);
        Message_Digest[i++] = (uint8_t)(context->Intermediate_Hash[i2] >> 16);
        Message_Digest[i++] = (uint8_t)(context->Intermediate_Hash[i2] >> 8);
        Message_Digest[i++] = (uint8_t)(context->Intermediate_Hash[i2++]);
    }
#else /* !USE_32BIT_ONLY */
    for (i = 0; i < HashSize; ++i)
        Message_Digest[i] = (uint8_t)
        (context->Intermediate_Hash[i >> 3] >> 8 * (7 - (i % 8)));
#endif /* USE_32BIT_ONLY */

    return shaSuccess;
}

